1. Field of the Invention
The present invention relates to a sheet feeding device and an image processing apparatus using the same, and more particularly to a sheet feeding device with a grooved elastic pad and an image processing apparatus using the same.
2. Related Art
A conventional sheet separator of a scanner is usually composed of a feeding roller and a friction pad. FIG. 9 is a schematic illustration of a conventional friction pad 210 combined with a feeding roller 220. As shown in FIG. 9, a nip is formed between the feeding roller 220 and the friction pad 210 mounted on a body 230. The feeding roller 220 and the friction pad 210 separate an individual sheet (the bottommost sheet, in this case) from the stack of sheets SS, relying on the difference of the frictions there among the sheets SS, the feeding roller 220 and the friction pad 210. By this means, the individual sheet is being fed in and transported to the scan region.
The curvilinear relationship of the position X in the sheet-feeding direction versus the static friction force Fsf being produced is shown in FIG. 9. Because the friction pad 210 is a rubber pad of uniform thickness, it cannot apply uniform pressures on the feeding roller 220 along the entire length of the nip; and only at a small part of the nip, a sufficient amount of friction is generated for use of separating the sheets SS. Due to the concentrated pressures on this small part of the friction pad 210, the friction pad 210 tends to wear out sooner than expected and consequently, decline in the quality of the sheet separation function will take place.